Heretofore, it has been well known to provide edgewise brackets having a single tie wing with a labially facing archwire slot, and it has been believed that the continuous slot extending between the mesial and distal sides of the bracket has interfered with efficient tooth movement objectives because of the friction generated between the archwire and the bracket which may inhibit smooth sliding movement of the bracket along the archwire.
While it is also well known that a single tie wing bracket is usually stronger than a double tie wing bracket, bracket strength is often sacrificed for the double wing bracket in order to permit a ligature to be applied to one of the wings during treatment to achieve desired tooth movement in relation to other teeth. Sacrificing bracket strength can lead to bracket failure which interrupts and extends the treatment time.
It is also known that with the standard double wing edgewise bracket, some discomfort may be experienced because of the relatively narrow gingival and incisal edges of the tie wing tips and the relatively large distances between the tie wing tips defined by this configuration. Typical edgewise brackets of this type are illustrated in U.S. Pat. Nos. 4,415,330 and 4,659,309.